we wondered, why the difference. so we asked our senior correspondent, john miller, who is a former deputy commissioner of the new york city police department, to join us from new orleans tonight. john, why is new york city enjoying record-low violence when the violence is so high in chicago, philadelphia, or new orleans? >> reporter: well, you look at new orleans. there's a celebration going on around here. but part of the reality is, this is one of the cities that leads the nation in murder, and the disparity, according to a police executive research forum study that brought all the police chiefs together, was it's what happens to the arrests after they get to court. now, take new york. they have a three- to five-year mandatory minimum. that means that if a gun charge ends up in front of a judge, you're almost certain to go to jail for three years. in chicago, you've got a 50-50 chance that you're not going to do any jail time almost. 33% of those cases are dismissed outright. >> pelley: so if you're caught with a gun in new york, whether you have used it in a crime or not, you're going to jail for three to five years, but not in chicago.